Adjustable exhaust baffling device

ABSTRACT

An exhaust baffling assembly which allows for the operator of a motor vehicle to select between two or more modes varying between maximum noise control, and maximum performance. This device is easily installed in most motorcycle after-market exhaust systems by removing the supplied baffle, and mounting the presented device in the same mounting hole, making for a modification free installation. After this device is installed, the mode selections offered can be selected at the operators discretion by hand, and without tools.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the baffling device placed in the exhaust stream of an internal combustion engine. Specifically, it relates to a device that allows the operator to choose between varying noise control and performance levels.

2. Description of the Prior Art

Internal combustion engines that have been tuned for high performance such as those found in race cars or motorcycles, often include an exhaust system that lacks any substantial noise control device. This is necessarily the case, since noise control devices often impose restrictions to flow which would hinder the performance of these engines.

Often the described vehicles are operated in residential areas where noise level mandates dictate a maximum lawful level of noise that may be produced by on-road vehicles.

There are some devices currently available that offer a compromise between noise control, and performance. One of these devices is often referred to as an exhaust cutout. This device is placed in-line with a conventional exhaust designed for noise control, and when activated a shorter secondary path that is designed for performance opens creating a less restrictive path through which the exhaust will flow. This type of device would be difficult to fit in tight applications on cars, and nearly impossible to practically install on a motorcycle.

Another method that has been devised is demonstrated in U.S. Pat. No. 4,541,506. This patent describes a product which would require extensive exhaust modification in order to adapt this product. Many times the required modification may not be desirable or even possible in the given application.

The main objective of this invention is to offer an improved device that is easily installed within the existing exhaust system with little or no modification, and permits the operator to select the desired balance of noise control and performance without tools.

BRIEF SUMMARY OF THE INVENTION

The presented invention is intended to offer an improved exhaust baffling device that offers two or more modes of varying noise and performance levels. The device has a rotating baffle assembly that in one extreme position restricts exhaust flow to control noise level of the exhaust, and in the other extreme position allows for as little restriction as possible to maximize engine performance. This device is easily installed without significant exhaust system modification and adjustable to any of the two or more positions without tools.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an exhaust system with the present invention installed and positioned in performance mode.

FIG. 2 is an enlarged sectional view taken from line 2-2 from FIG. 1.

FIG. 3 is a detailed view of the locking bosses taken on line 3-3 from FIG. 2.

FIG. 4 is an isometric view showing the complete assembly in the noise control mode.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a top view of the present invention generally designated 10 installed in a section of an existing exhaust system 24.

FIG. 2 illustrates two primary parts of the device. The first part is the tubular body 11 which creates the main body of the device. The second primary part is the baffle assembly generally designated 12 which provides the operational mode change as described by the present invention.

The baffle assembly 12 consists of two baffle plates 13 connected by two lifting tabs 14. The lifting tabs 14 provide for a means of lifting axially, and rotating about the pivot shaft 15. Each baffle plate 13 has a varying quantity, size, and pattern of passages 17 through which exhaust gas may pass when place transverse to exhaust flow. Each baffle plate 13 has a locking tab 18 that extends towards the tubular body 11 where there are corresponding slots that receive said tabs causing the baffle assembly 12 to rotationally lock in a position when acted upon by the spring 19.

FIG. 3 illustrates the locking boss features 20, 21, 22 and 23. These features create four potential operating modes of the invention.

The tubular body 11 may include one or more holes 16 on its perimeter that may be used for mounting the device 10 into the existing exhaust system 24.

To provide noise level control the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until locking tabs 18 have been completely removed from locking boss 23. The baffle assembly 12 can then be rotated about pivot shaft 15 until locking tabs 18 are in alignment with locking boss 20. When the baffle assembly 12 is released the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage into locking boss 20. Doing so positions the baffle assembly 12 transverse to exhaust flow significantly reducing the open area in the exhaust passage. When the open area of the exhaust is reduced in this manner back pressure in the exhaust upstream from the invention increases thus providing the noise control desired.

When performance mode is desired and noise control is no longer needed, the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until the locking tabs 18 have been completely removed from the locking boss 20. The baffle assembly 12 can then be rotated about pivot shaft 15 until the locking tabs 18 are in alignment with locking boss 23. When released the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage locking boss 23. Doing so positions the baffle assembly 12 generally parallel to exhaust flow, maximizing open area through which the exhaust can flow. When maximum open area is provided, performance of the vehicle will be maximized.

In addition to performance mode, and noise control mode this invention offers one or more hybrid modes. These modes offer a balance of noise control and performance. If a hybrid mode is desired the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until the locking tabs 18 have been completely removed from the locking boss in which it is currently positioned. The baffle assembly 12 can then be rotated about the pivot shaft 15 until locking tabs 18 are in alignment with either locking boss 21 or 22 depending on the hybrid mode desired. When released, the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage the selected locking boss, 21 or 22. 

I claim:
 1. An exhaust baffling device comprised of a tubular body defining a central passageway in communication with an engine exhaust system, designed for installation into an existing exhaust system with minimal or no system modification, said tubular body includes tab receiving apertures defining at least two positions; movable baffle plate assembly comprised of at least one baffle plate with a number of apertures, positioned in said central passageway of said tubular body and positionable between two or more angular positions relative to exhaust gas flow through tubular body, positioning means provided by tabs extending from said baffle plate toward said receiving apertures in said tubular body, said tab being of sufficient length to engage said receiving aperture, and designed to disengage position defining aperture upon axial movement of said baffle assembly; pivot shaft extending through said central passageway fixed relative to said tubular body about which said baffle assembly is rotationally and axially movable thereon; a compression spring positioned coaxially with said pivot shaft between said tubular body and said baffle plate assembly urging said baffle plate assembly toward said tubular body in order to engage said receiving apertures in said tubular body; allowing for tool-less positioning of said baffle plate assembly.
 2. An exhaust baffling device according to claim 1, wherein said baffle assembly includes two baffle plates positioned 180 degrees apart, where said baffle plate contains a number of apertures dictating the amount of open cross-sectional area when the baffle assembly is positioned transverse to the flow of exhaust gas; and tubular body includes tab receiving apertures which dictate four potential locating positions for said baffle assembly, one extreme position locating said baffle assembly generally transverse to the flow of exhaust gas in which the open cross-sectional area is at its lowest, the other extreme position locating the baffle assembly in general alignment with the flow of exhaust gas in which the open cross-sectional area is highest, and two additional positions between said extreme positions offering optional amounts of open cross-sectional area. 